The present invention relates in general to a printer and more particularly to a paper separation (or release) apparatus and paper separation method which are applicable to an image or picture formation apparatus as a printer for printing and image formation on a continuous, sequence paper.
FIG. 8 shows a general structure of a high-speed printer for a continuous, sequence paper. In a case that a continuous, sequence paper is not set to this high speed printer, or in a case that discontinuous papers (in a bundle) are set by some unknown reasons in place of the continuous, sequence paper and therefore reset is to be made, a continuous, sequence paper P of a paper buffer portion 200 is set in an auto-load portion 201 and then a start switch for the auto-load portion (not shown) is put on, so that the paper P is automatically fed to a transfer portion 202, a fixture portion 203 and a stacker portion 204. By this operation, the continuous, sequence paper P is on a stand-by state for a printing operation. The serial, consecutive paper-loading operation is called as an auto-load operation.
Japanese Patent Publications (unexamined) No. 9-90775 (1997) and No. 3-13444 (1991) show structures in which a continuous, sequence paper P is fed from a transfer drum and guided to a fixture portion 203 and a stacker portion 204 through some guides. An example of such a guide construction and a pinch roller construction is shown in FIG. 9, by which a paper loading operation is conducted in the transfer portion 202 at the time of an auto-load operation. The paper P which is fed from an auto-load table portion (that is, a table provided in the auto-load portion 201 shown in FIG. 8) is fed by a lower pin 102 of transfer portion and then fed upward as it is closely contacted with the transfer drum 103. The paper P closely contacted with the transfer drum 103 is abutted against a guide 104, which has a minor gap (approximately, 0.8 mm) relative to the drum 103 and then released. Then, the paper P is pulled by the pinch roller 105 so that apertures of the paper P are engaged with upper pins 106 of the tractor of the transfer portion.
The pinch roller 105 is, as shown in FIG. 10, generally stands by at an upper portion of the feeding direction of the paper P. When the paper P is fed to advance by the auto-load operation, the pinch roller is moved upward relative to the feeding direction of the paper P and, as shown In FIG. 11, serves to hold the paper P to feed it toward the tractor upper pin 106.
However, as a continuous, sequence paper, which is usually referred as a continuous form P, has recently been used extensively and, when such a thin paper is used and fed into the transfer portion 202, it is likely that the thin paper is freely delivered through a space between the transfer drum 103 and the guide member 104 without a required contact by these members 103 and 104 with the result that there is a problem of unavailability of the auto-loading.
With respect to separation of a paper, an attempt was made to provide a paper releasing nail for releasing a paper as disclosed in Japanese Utility Model Publication (unexamined) No. 5-20072 (1993). However, this technique does not permit the paper to be released from a circumferential surface of the transfer drum and therefore is not a good measure for solving the problems described above. Further, Japanese Patent Publication (unexamined) No. 2-238480 (1990) discloses a structure in which a paper releasing nail is provided to a paper supporting drum which supports a paper for feeding, but this attempt does not release a paper from a circumferential surface of the transfer drum and, therefore, the aforementioned problems have not been solved yet. In view of the structural feature of the transfer drum, the paper releasing nail as described above sometimes provides damages on the surface of the drum at the time of releasing operation of the paper from the drum surface by the use of the nail and, therefore, results in damages in the circumferential surface of the drum and generation of undesirable noises in printing and image or picture. Thus, use of the paper releasing nail as described above results in deterioration of printing and image (picture) properties. In the structure disclosed in the above-described Publication No. 2-238480, the paper is released from the circumferential surface of the drum during the paper feeding operation by means of the releasing nail, and this is not a paper releasing from a circumferential surface of the transfer drum and, therefore, this method is applicable.
On the other hand, provided that there should be a suggestive structure of a paper-separation nail for separating a paper from the transfer drum, it must be that this structure will have the structure as follows. Namely, it must be constructed such that the paper release nail is contacted with the circumferential surface of the transfer drum 103 at the time of auto-loading mode only and, further, a paper releasing operation must be finished by the nail before the pinch roller is driven for the above-mentioned pulling operation. Apart from the operational structure of the pinch roller 105, if it is required to provide a controlling device for controlling the operation of the paper separation nail, additional mechanism must be provided for a synchronous operation with the pinch roller 105. This, however, will provide a new serious problem of complexity in mechanical structure.
In view of the foregoing, an object of the present invention is to provide an improvement in a method and apparatus of paper separation which permit a secure and reliable auto-loading operation of paper separation with less complex mechanism of the apparatus.
According to the present invention, there is provided a paper separation apparatus which comprises a paper separation body for separating a paper from a transfer body; a paper feeding supporter device for holding the paper firmly and supporting the feed of the paper; and a link mechanism for moving the paper separation body toward a circumferential surface of the transfer body so as to separate the paper from the transfer body in an auto-loading step and moving at least a portion of the paper feeding supporter device to thereby hold firmly the separated paper, so that the movement of the paper separation body is co-acted in synchronism with the movement of the paper feeding supporter device.
In the structure described above, when the continuous, sequence paper is fed to the transfer body at the time of the auto-loading operation, the paper separation body is moved toward the circumferential surface of the transfer body by means of the link mechanism, at the moment of which a movement of the paper feeding supporter can be started if desired, the paper is separated from the transfer body. Then, by the link mechanism, at least a part of the paper feeding supporter is further moved to thereby hold the separated paper by the paper feeding supporter and, after that, the paper feeding operation is enhanced by the paper feeding supporter.
As described above, the operation of the paper separation body and the operation of the paper feeding supporter are co-acted with each other in synchronism and this synchronized operation permits a reliable paper separation and auto-loading operation.
The paper feeding supporter device preferably includes at least a pinch roller but is not limited to this structure, and any other structure can be used so long as it can hold the continuous, sequence paper and feed the same to a lower portion of the structure. According to the present invention, it is defined in the claim that, by the link mechanism described above, at least a part of the paper feeding supporter device is moved. This means that if at least one of the rollers (preferably, a pinch roller) is moved by the link mechanism as defined in the claim, the remaining other roller can serve to hold the paper.
The paper separation body preferably has a paper separation nail which can release or separate the paper, and it is further preferred that the paper separation nail can be rotated in the paper feeding direction. By the rotational mechanism of the paper separation nail, no damage or injure is produced on the circumferential surface of the transfer body by the link mechanism when the paper separation nail is contacted with the circumferential surface of the transfer body.
In an embodiment of the paper separation apparatus, the structure comprises a paper feeding supporter device for holding a paper and supporting the paper to be fed; a link mechanism for moving at least a part of the paper feeding supporter device to thereby hold the paper in an auto-loading operation; and a paper separation body for separating the paper from the transfer body so that the link mechanism is operated in synchronism with the paper feeding supporter device to thereby move the paper separation body toward a circumferential surface of the transfer body and separate the paper from the transfer body immediately before the paper feeding supporter device holds the paper.
In this structure, the link mechanism which serves to move the paper feeding supporter device is provided with a function for moving synchronously the paper feeding supporter device with the paper separation body. These movements are operated by a single link mechanism and, therefore, an operational structure for the paper feeding supporter device is separately and independently provided from an operational structure for the paper separation body. In this structure, additional synchronism mechanism for synchronously operating these movements will not required.
In a further feature of the invention, there is provided a method which has the steps of separating a paper which has been fed by moving a paper separation body toward a circumferential surface of a transfer body, moving at least a part of a paper feeding supporter device in synchronism with the movement of the paper separation body, and holding the separated paper to thereby support a paper feeding operation.